WO2023055131A1 - Polyimide film comprising graphene nanoplatelets and method for manufacturing same - Google Patents

Abstract

The present invention provides a polyimide film that is obtained by imidizing a polyamic acid solution containing a dianhydride component including benzophenonetetracarboxylic dianhydride (BTDA), biphenyltetracarboxylic dianhydride (BPDA) and pyromellitic dianhydride (PMDA), and a diamine component including m-tolidine and paraphenylene diamine (PPD)), and comprises graphene nanoplatelets in an amount of 0.5-2.5% by weight.

Description

Polyimide film containing graphene nanoplatelets and manufacturing method thereof

The present invention relates to a polyimide film containing graphene nanoplatelets with excellent dielectric properties and a method for preparing the same.

Polyimide (PI) is a polymer material with the highest level of heat resistance, chemical resistance, electrical insulation, chemical resistance and weather resistance among organic materials based on an imide ring with excellent chemical stability along with a rigid aromatic main chain. am.

In particular, it is in the spotlight as a high-functional polymer material in the fields of electricity, electronics, and optics due to its excellent insulating properties, that is, excellent electrical properties such as low permittivity.

BACKGROUND ART [0002] In recent years, as electronic products have been reduced in weight and size, highly integrated and flexible thin circuit boards have been actively developed.

Such a thin circuit board tends to use a structure in which a circuit including a metal foil is formed on a polyimide film that has excellent heat resistance, low temperature resistance, and insulation characteristics and is easily bent.

As such a thin circuit board, a flexible metal clad laminate is mainly used, and as an example, a flexible copper clad laminate (FCCL) using a thin copper plate as a metal foil is included. In addition, polyimide is also used as a protective film or insulating film for thin circuit boards.

On the other hand, as various functions are inherent in recent electronic devices, fast calculation and communication speeds are required for the electronic devices, and to meet these requirements, thin circuit boards capable of high-speed communication at high frequencies are being developed.

In order to realize high-frequency high-speed communication, an insulator having high impedance capable of maintaining electrical insulation even at high frequencies is required. Since impedance is in inverse proportion to the frequency and dielectric constant (Dk) formed in the insulator, the dielectric constant must be as low as possible to maintain insulation even at high frequencies.

However, in the case of normal polyimide, dielectric properties are not at a level that is excellent enough to maintain sufficient insulation in high frequency communication.

In addition, it is known that as an insulator has a low dielectric characteristic, generation of undesirable stray capacitance and noise can be reduced in a thin circuit board, and thus, the causes of communication delay can be largely eliminated.

Therefore, polyimide with low dielectric properties is recognized as the most important factor in the performance of thin circuit boards.

In particular, in the case of high-frequency communication, dielectric dissipation inevitably occurs through polyimide. Dielectric dissipation factor (Df) means the amount of electrical energy wasted on a thin circuit board and is closely related to the signal propagation delay that determines the communication speed. It is recognized as an important factor in the performance of the substrate.

In addition, the higher the moisture contained in the polyimide film, the higher the dielectric constant and the higher the dielectric loss factor. In the case of polyimide film, while it is suitable as a material for a thin circuit board due to its excellent inherent properties, it may be relatively vulnerable to moisture due to a polar imide group, and as a result, insulation properties may be deteriorated.

Therefore, it is necessary to develop a polyimide film having dielectric properties that maintains mechanical properties peculiar to polyimide at a certain level.

In addition, recently, in order to solve the problem that the reflected signal disturbs the rising time part and interferes with the semiconductor operation as the transmission speed increases, a method of absorbing energy by attaching a terminator to the end of the circuit is applied. . To apply this absorption method, the impedance of the terminator and the impedance of the transmission circuit must be the same.

At this time, since the impedance value of the terminator resistor is fixed, it is necessary to adjust the impedance of the circuit of the printed circuit board (PCB).

That is, while the impedance decreases as the insulation thickness becomes thinner due to the trend of miniaturization of electronic devices, the dielectric constant must be higher than that of the conventional polyimide film (Dk: 3.5) in order to match the impedance value of the terminator resistance.

[Prior art literature]

[Patent Literature]

(Patent Document 1) Korean Patent Publication No. 10-2015-0069318

Accordingly, in order to solve the above problems, an object of the present invention is to provide a polyimide film having excellent dielectric properties and a manufacturing method thereof.

Accordingly, the present invention has a practical purpose to provide specific embodiments thereof.

One embodiment of the present invention for achieving the above object is benzophenone tetracarboxylic dianhydride (BTDA), biphenyltetracarboxylic dianhydride (BPDA) and pyromellitic dianhydride (PMDA) Obtained by imidization reaction of a dianhydride component containing a polyamic acid solution containing a diamine component including m-tolidine and paraphenylene diamine (PPD), graphene nanoplates (graphene It provides a polyimide film containing 0.5 to 2.5% by weight of nanoplatelets).

Based on 100 mol% of the total content of the diamine component, the content of m-tolidine may be 20 mol% or more and 40 mol% or less, and the content of paraphenylene diamine may be 60 mol% or more and 80 mol% or less.

In addition, the content of benzophenone tetracarboxylic dianhydride is 20 mol% or more and 45 mol% or less based on 100 mol% of the total content of the dianhydride component, and the content of biphenyltetracarboxylic dianhydride is 20 mol % or more and 45 mol% or less, and the content of pyromellitic dianhydride may be 20 mol% or more and 45 mol% or less.

The graphene nanoplatelets may have an average thickness of 6 to 8 nm, an average particle size of 5 to 25 μm, and a specific surface area of 120 to 150 m ² /g.

Meanwhile, the polyimide film may have a dielectric constant of 4.0 or more and 7.0 or less, and a dielectric loss factor of 0.01 or less.

Another embodiment of the present invention is (a) dianhydride acids including benzophenonetetracarboxylic dianhydride (BTDA), biphenyltetracarboxylic dianhydride (BPDA) and pyromellitic dianhydride (PMDA) preparing a polyamic acid by polymerizing a component and a diamine component composed of m-tolidine and paraphenylene diamine (PPD) in an organic solvent, (b) adding graphene nanoplatelets to the polyamic acid and mixing; and (c) imidizing the polyamic acid containing the graphene nanoplatelets.

Another embodiment of the present invention provides a multilayer film including the polyimide film, a flexible metal clad laminate including the polyimide film and an electrically conductive metal foil, and an electronic component including the flexible metal clad laminate.

As described above, the present invention provides a polyimide film having excellent dielectric properties through a polyimide film composed of specific components and a specific composition ratio and a method for manufacturing the polyimide film, thereby providing a polyimide film in various fields requiring these characteristics, particularly flexible metal clad laminates, etc. It can be usefully applied to electronic parts of

Hereinafter, embodiments of the present invention will be described in more detail in the order of "polyimide film" and "method for producing polyimide film" according to the present invention.

Prior to this, the terms or words used in this specification and claims should not be construed as being limited to the usual or dictionary meaning, and the inventor appropriately uses the concept of the term in order to explain his/her invention in the best way. It should be interpreted as a meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined.

Therefore, since the configuration of the embodiments described in this specification is only one of the most preferred embodiments of the present invention and does not represent all of the technical spirit of the present invention, various equivalents and modifications that can replace them at the time of the present application It should be understood that examples may exist.

In this specification, singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as "comprise", "comprise" or "having" are intended to indicate that there is an embodied feature, number, step, component, or combination thereof, but one or more other features or It should be understood that the presence or addition of numbers, steps, components, or combinations thereof is not precluded.

When amounts, concentrations, or other values or parameters herein are given as ranges, preferred ranges, or recitations of upper preferred and lower preferred values, any pair of any upper range limits, whether or not the ranges are separately disclosed, or It should be understood as specifically disclosing the preferred values and any lower range limits or all ranges formed from preferred values.

When a range of numerical values is recited herein, the range is intended to include its endpoints and all integers and fractions within the range, unless stated otherwise. It is intended that the scope of the present invention not be limited to the specific values recited when defining the range.

As used herein, “dianhydride acid” is intended to include its precursors or derivatives, which technically may not be dianhydride acids, but will nonetheless react with diamines to form polyamic acids, which in turn polyamic acids. can be converted to mead.

As used herein, "diamine" is intended to include precursors or derivatives thereof, which may not technically be diamines, but will nonetheless react with dianhydrides to form polyamic acids, which in turn will form polyamic acids. can be converted to mead.

In the present specification, “to” and “~” in “a to b” and “a to b” representing numerical ranges are defined as ≥ a and ≤ b.

The polyimide film according to the present invention includes a dianhydride component including benzophenonetetracarboxylic dianhydride (BTDA), biphenyltetracarboxylic dianhydride (BPDA) and pyromellitic dianhydride (PMDA), It is obtained by imidization of a polyamic acid solution containing a diamine component including m-tolidine and paraphenylene diamine (PPD), and graphene nanoplatelets are 0.5 to 2.5% by weight. can include

Based on 100 mol% of the total content of the diamine component, the content of m-tolidine may be 20 mol% or more and 40 mol% or less, and the content of paraphenylene diamine may be 60 mol% or more and 80 mol% or less.

In particular, m-tolidine has a hydrophobic methyl group, contributing to the low moisture absorption characteristics of the polyimide film.

Based on 100 mol% of the total content of the dianhydride component, the content of benzophenonetetracarboxylic dianhydride is 20 mol% or more and 45 mol% or less, and the content of biphenyltetracarboxylic dianhydride is 20 mol% or more 45 mol% or less, and the content of pyromellitic dianhydride may be 20 mol% or more and 45 mol% or less.

The polyimide chain derived from the biphenyltetracarboxylic dianhydride of the present invention has a structure called a charge transfer complex (CTC), that is, an electron donor and an electron acceptor. They have a regular linear structure located close to each other, and intermolecular interactions are strengthened.

In addition, benzophenonetetracarboxylic dianhydride having a carbonyl group also contributes to the expression of CTC like biphenyltetracarboxylic dianhydride.

Since this structure has an effect of preventing hydrogen bonding with moisture, it is possible to maximize the effect of lowering the hygroscopicity of the polyimide film by influencing the lowering of the moisture absorptivity.

In one specific example, the dianhydride component may additionally include pyromellitic dianhydride. Pyromellitic dianhydride is a dianhydride component having a relatively rigid structure, and is preferable in that it can impart appropriate elasticity to the polyimide film.

In order for the polyimide film to simultaneously satisfy appropriate elasticity and moisture absorptivity, the content ratio of dianhydride is particularly important. For example, as the content ratio of biphenyltetracarboxylic dianhydride decreases, it becomes difficult to expect a low moisture absorption due to the CTC structure.

In addition, biphenyltetracarboxylic dianhydride and benzophenonetetracarboxylic dianhydride contain two benzene rings corresponding to the aromatic part, whereas pyromellitic dianhydride has a benzene ring corresponding to the aromatic part contains 1

The increase in the pyromellitic dianhydride content in the dianhydride component can be understood as an increase in the imide group in the molecule based on the same molecular weight, which means that the polyimide polymer chain has an imide derived from the pyromellitic dianhydride. It can be understood that the ratio of de groups is increased relative to the imide groups derived from biphenyltetracarboxylic dianhydride and benzophenonetetracarboxylic dianhydride.

That is, an increase in the content of pyromellitic dianhydride can be seen as a relative increase in the imide group with respect to the entire polyimide film, and as a result, it is difficult to expect a low moisture absorption rate.

Conversely, when the content ratio of pyromellitic dianhydride is decreased, the component having a relatively rigid structure is reduced, and thus the elasticity of the polyimide film may be lowered to a desired level or less.

For this reason, when the content of biphenyltetracarboxylic dianhydride and benzophenonetetracarboxylic dianhydride exceeds the above range or the content of pyromellitic dianhydride is below the above range, the polyimide film Mechanical properties are lowered, and heat resistance at a level suitable for manufacturing a flexible metal clad laminate cannot be secured.

Conversely, when the content of biphenyltetracarboxylic dianhydride and benzophenonetetracarboxylic dianhydride is less than the above range or the content of pyromellitic dianhydride exceeds the above range, an appropriate level of dielectric It is difficult to achieve a constant, dielectric loss rate and moisture absorptive rate, which is undesirable.

Meanwhile, the graphene nanoplatelets may have an average thickness of 6 to 8 nm, an average particle size of 5 to 25 μm, and a specific surface area of 120 to 150 m ² /g.

The graphene nanoplatelets have relatively excellent dispersibility compared to other carbon nanomaterials, and when added to a polyimide film, a drop in dielectric loss of the polyimide film can be minimized.

* In one embodiment, the polyimide film may have a dielectric constant of 4.0 or more and 7.0 or less, and a dielectric loss factor of 0.01 or less.

The dielectric constant may be preferably 4.5 or more, more preferably 5.0 or more.

In this regard, in the case of a polyimide film satisfying both dielectric constant (Dk) and dielectric loss factor (Df), it can be used as an insulating film for flexible metal clad laminates, and the manufactured flexible metal clad laminates transmit signals at high frequencies of 10 GHz or more. Even when used as an electrical signal transmission circuit, its insulation stability can be secured and signal transmission delay can be minimized.

Production of polyamic acid in the present invention, for example,

(1) A method in which the entire amount of the diamine component is placed in a solvent, and thereafter a dianhydride component is added so as to be substantially equimolar to the diamine component, followed by polymerization;

(2) a method in which the entire amount of the dianhydride component is placed in a solvent, and then a diamine component is added so as to be substantially equimolar to the dianhydride component, followed by polymerization;

(3) After putting some of the diamine components in a solvent, mixing some of the dianhydride components at a ratio of about 95 to 105 mol% with respect to the reaction components, and then adding the remaining diamine components, followed by the remaining dianhydride components. a method of polymerizing by adding components so that the diamine component and the dianhydride component are substantially equimolar;

(4) After putting the dianhydride component in the solvent, some components of the diamine compound are mixed in a ratio of 95 to 105 mol% with respect to the reaction components, then another dianhydride component is added, and then the remaining diamine components are added, a method of polymerizing the diamine component and the dianhydride component so that they are substantially equimolar;

(5) Some diamine components and some dianhydride components are reacted in an excess amount in a solvent to form a first composition, and some diamine components and some dianhydride components in another solvent are reacted in an excess amount to form a first composition. A method of mixing the first and second compositions after forming two compositions, and completing the polymerization. At this time, if the diamine component is excessive when forming the first composition, the second composition contains an excess of the dianhydride component And, when the dianhydride component is excessive in the first composition, the diamine component is excessive in the second composition, and the first and second compositions are mixed so that the entire diamine component and the dianhydride component used in these reactions are substantially equal. The method of polymerizing by making it mole, etc. are mentioned.

However, the polymerization method is not limited to the above examples, and any known method may be used for preparing the polyamic acid.

In one specific example, the method for producing a polyimide film according to the present invention,

(a) dianhydride components including benzophenone tetracarboxylic dianhydride (BTDA), biphenyltetracarboxylic dianhydride (BPDA) and pyromellitic dianhydride (PMDA), and m-tolidine ( preparing a polyamic acid by polymerizing a diamine component composed of m-tolidine) and paraphenylene diamine (PPD) in an organic solvent;

(b) adding and mixing graphene nanoplatelets to the polyamic acid; and

(c) imidizing the polyamic acid containing the graphene nanoplatelets.

Based on 100 mol% of the total content of the diamine component, the content of m-tolidine is 20 mol% or more and 40 mol% or less, the content of paraphenylene diamine is 60 mol% or more and 80 mol% or less, and the dianhydride component is Based on the total content of 100 mol%, the content of benzophenonetetracarboxylic dianhydride is 20 mol% or more and 45 mol% or less, and the content of biphenyltetracarboxylic dianhydride is 20 mol% or more and 45 mol% or less And, the content of pyromellitic dianhydride may be 20 mol% or more and 45 mol% or less.

In the present invention, the polymerization method of the polyamic acid as described above can be defined as a random polymerization method, and the polyimide film prepared from the polyamic acid of the present invention manufactured by the above process has excellent dielectric properties It can be preferably applied in terms of maximizing the effect of the invention.

However, since the polymerization method produces a relatively short length of the repeating unit in the polymer chain described above, there may be limitations in exhibiting the excellent properties of each polyimide chain derived from the dianhydride component. Therefore, the polymerization method of the polyamic acid that can be particularly preferably used in the present invention may be a block polymerization method.

On the other hand, the solvent for synthesizing the polyamic acid is not particularly limited, and any solvent can be used as long as it dissolves the polyamic acid, but an amide-based solvent is preferable.

Specifically, the solvent may be an organic polar solvent, and in detail, may be an aprotic polar solvent, for example, N,N-dimethylformamide (DMF), N,N- It may be one or more selected from the group consisting of dimethylacetamide, N-methyl-pyrrolidone (NMP), gamma butyrolactone (GBL), and diglyme, but is not limited thereto, and is used alone or as needed. Two or more types can be used in combination.

In one example, N,N-dimethylformamide and N,N-dimethylacetamide may be particularly preferably used as the solvent.

In addition, in the polyamic acid manufacturing process, a filler may be added for the purpose of improving various properties of the film, such as sliding properties, thermal conductivity, corona resistance, and loop hardness. The filler added is not particularly limited, but preferable examples include silica, titanium oxide, alumina, silicon nitride, boron nitride, calcium hydrogen phosphate, calcium phosphate, mica and the like.

The particle size of the filler is not particularly limited, and may be determined according to the film properties to be modified and the type of filler to be added. Generally, the average particle size is 0.05 to 100 μm, preferably 0.1 to 75 μm, more preferably 0.1 to 50 μm, particularly preferably 0.1 to 25 μm.

When the particle diameter is less than this range, the modification effect becomes difficult to appear, and when it exceeds this range, surface properties may be greatly damaged or mechanical properties may be greatly reduced.

Further, the addition amount of the filler is not particularly limited either, and may be determined according to the properties of the film to be modified, the particle size of the filler, and the like. Generally, the added amount of the filler is 0.01 to 100 parts by weight, preferably 0.01 to 90 parts by weight, and more preferably 0.02 to 80 parts by weight, based on 100 parts by weight of the polyimide.

If the added amount of the filler is less than this range, the modification effect by the filler is difficult to appear, and if it exceeds this range, the mechanical properties of the film may be significantly damaged. The method of adding the filler is not particularly limited, and any known method may be used.

In the production method of the present invention, the polyimide film may be prepared by thermal imidation or chemical imidation.

In addition, it may be prepared by a complex imidation method in which thermal imidation and chemical imidation are combined.

The thermal imidization method is a method of inducing an imidization reaction by excluding a chemical catalyst and using a heat source such as hot air or an infrared dryer.

* In the thermal imidation method, the amic acid group present in the gel film may be imidized by heat-treating the gel film at a variable temperature in the range of 100 to 600 ° C, specifically 200 to 500 ° C, more specifically , Heat treatment at 300 to 500 ° C. may imidize the amic acid group present in the gel film.

However, some of the amic acid (about 0.1 mol% to 10 mol%) may be imidized even in the process of forming the gel film. This may also be included in the scope of the thermal imidization method.

In the case of chemical imidation, a polyimide film may be prepared using a dehydrating agent and an imidizing agent according to a method known in the art.

As an example of the composite imidization method, a dehydrating agent and an imidizing agent are added to a polyamic acid solution, and then heated at 80 to 200 ° C, preferably 100 to 180 ° C, partially cured and dried, and then heated at 200 to 400 ° C for 5 to 400 seconds. A polyimide film can be manufactured by heating.

The polyimide film of the present invention manufactured according to the above manufacturing method may have a dielectric constant of 4.0 or more and 7.0 or less, and a dielectric loss factor of 0.01 or less.

The present invention provides a multilayer film comprising the above-described polyimide film and a flexible metal-clad laminate comprising the above-described polyimide film and electrically conductive metal foil.

The multilayer film may include a thermoplastic resin layer, particularly a thermoplastic polyimide resin layer.

The metal foil used is not particularly limited, but in the case of using the flexible metal clad laminate of the present invention for electronic devices or electrical devices, for example, copper or copper alloy, stainless steel or its alloy, nickel or nickel alloy (42 alloy) Also included), it may be a metal foil containing aluminum or aluminum alloy.

In general flexible metal clad laminates, copper foils such as rolled copper foil and electrolytic copper foil are often used, and they can be preferably used in the present invention as well. Moreover, a rust prevention layer, a heat resistance layer, or an adhesive layer may be applied to the surface of these metal foils.

In the present invention, the thickness of the metal foil is not particularly limited, and may be any thickness capable of exhibiting sufficient functions depending on its use.

In the flexible metal clad laminate according to the present invention, a metal foil is laminated on one surface of the polyimide film, or an adhesive layer containing thermoplastic polyimide is added to one surface of the polyimide film, and the metal foil is attached to the adhesive layer. It may be a laminated structure.

The present invention also provides an electronic component including the flexible metal clad laminate as an electrical signal transmission circuit. The electrical signal transmission circuit may be an electronic component that transmits a signal at a high frequency of at least 2 GHz, specifically at a high frequency of at least 5 GHz, and more specifically at a high frequency of at least 10 GHz.

The electronic component may be, for example, a communication circuit for a portable terminal, a communication circuit for a computer, or a communication circuit for aerospace, but is not limited thereto.

Hereinafter, the action and effect of the invention will be described in more detail through specific examples of the invention. However, these embodiments are only presented as examples of the invention, and the scope of the invention is not determined thereby.

<Production Example>

Inject DMF while injecting nitrogen into a 500 ml reactor equipped with a stirrer and nitrogen inlet/discharge pipe, set the temperature of the reactor to 30 ° C or less, m-tolidine and paraphenylene diamine as diamine components, and dianhydride as components Benzophenone tetracarboxylic dianhydride, biphenyltetracarboxylic dianhydride and pyromellitic dianhydride were added to confirm complete dissolution.

Based on 100 mol% of the total content of the diamine component, the content of m-tolidine is 34 mol%, the content of paraphenylene diamine is 66 mol%, and based on 100 mol% of the total content of the dianhydride component, benzo The content of phenonetetracarboxylic dianhydride was 33 mol%, the content of biphenyltetracarboxylic dianhydride was 32 mol%, and the content of pyromellitic dianhydride was 35 mol%.

Thereafter, the temperature of the reactor was raised to 40 ° C. under a nitrogen atmosphere, and stirring was continued for 120 minutes while heating to prepare polyamic acid.

After adding the graphene nanoplatelets to the polyamic acid thus prepared, the mixture was stirred.

A catalyst and a dehydrating agent were added to the final polyamic acid prepared in this way, and air bubbles were removed through high-speed rotation of 1,500 rpm or more, and then applied to a glass substrate using a spin coater.

Thereafter, a gel film was prepared by drying at a temperature of 120 ° C. for 30 minutes under a nitrogen atmosphere, and the temperature was raised to 450 ° C. at a rate of 2 ° C./min, followed by heat treatment at 450 ° C. for 60 minutes, followed by 2 to 30 ° C. By cooling again at a rate of °C/min, a final polyimide film was obtained and peeled off from the glass substrate by dipping in distilled water.

The thickness of the prepared polyimide film was 15 μm. The thickness of the prepared polyimide film was measured using Anritsu's Electric Film thickness tester.

<Examples 1 and 2 and Comparative Examples 1 to 5>

It was prepared by the preparation example described above, but the content of the graphene nanoplatelets was adjusted as shown in Table 1.

	graphene nanoplatelets (weight%)	permittivity (Dk)	dielectric loss factor (Df)
Example 1	1.0	5.36	0.00538
Example 2	2.0	6.77	0.00761
Comparative Example 1	0	3.46	0.00440
Comparative Example 2	0.1	3.78	0.00460
Comparative Example 3	3.0	10.51	0.00877
Comparative Example 4	4.0	16.19	0.01245
Comparative Example 5	5.0	22.01	0.01521

<Experimental Example> Permittivity and dielectric loss rate evaluation

As shown in Table 1, dielectric constant and dielectric loss factor were measured for the polyimide films prepared in Examples 1 and 2 and Comparative Examples 1 to 5, respectively.

(1) Permittivity measurement

* Permittivity (Dk) was measured using Keysight's SPDR measuring instrument at 10 GHz.

(2) Dielectric loss factor measurement

The dielectric loss factor (Df) was measured by leaving the flexible metal clad laminate for 72 hours using an ohmmeter Agilent 4294A.

As shown in Table 1, the polyimide film prepared according to the embodiment of the present invention satisfies all conditions of dielectric constant of 4.0 or more and 7.0 or less, and dielectric loss factor of 0.01 or less.

The polyimide films of Comparative Examples 1 and 2 containing no or a small amount (0.1% by weight) of the graphene nanoplatelets had dielectric constants of less than 4.0.

In addition, Comparative Examples 3 to 5 including graphene nanoplatelets in excess (3% by weight or more) had dielectric constants exceeding 7.0, and in particular, Comparative Examples 4 and 5 also had dielectric loss factors exceeding 0.01.

Therefore, it can be confirmed that the dielectric constant and dielectric loss factor are at desired levels only within the content range of the graphene nanoplatelets according to the embodiment.

These results are achieved by the components and composition ratios specified herein, and it can be seen that the content of each component plays a decisive role.

On the other hand, the polyimide films of Comparative Examples 1 and 2 having components different from those of the Examples are used in electronic components in which signals are transmitted at high frequencies in units of giga units in at least one aspect of dielectric constant and dielectric loss factor compared to the polyimide films of Examples. Difficulties can be foreseen.

Although the above has been described with reference to the embodiments of the present invention, those skilled in the art will be able to make various applications and modifications within the scope of the present invention based on the above information.

As described above, the present invention provides a polyimide film having excellent dielectric properties through a polyimide film composed of specific components and a specific composition ratio and a method for manufacturing the polyimide film, thereby providing a polyimide film in various fields requiring these characteristics, particularly flexible metal clad laminates, etc. It can be usefully applied to electronic parts of

Claims (11)

1. dianhydride components including benzophenonetetracarboxylic dianhydride (BTDA), biphenyltetracarboxylic dianhydride (BPDA) and pyromellitic dianhydride (PMDA), and m-tolidine ) And obtained by imidization reaction of a polyamic acid solution containing a diamine component including paraphenylene diamine (PPD),

   Containing 0.5 to 2.5% by weight of graphene nanoplatelets,

   polyimide film.
2. According to claim 1,

   Based on 100 mol% of the total content of the diamine component, the content of m-tolidine is 20 mol% or more and 40 mol% or less, and the content of paraphenylene diamine is 60 mol% or more and 80 mol% or less,

   polyimide film.
3. According to claim 1,

   The content of benzophenone tetracarboxylic dianhydride is 20 mol% or more and 45 mol% or less based on 100 mol% of the total content of the dianhydride component,

   The content of biphenyltetracarboxylic dianhydride is 20 mol% or more and 45 mol% or less,

   The content of pyromellitic dianhydride is 20 mol% or more and 45 mol% or less,

   polyimide film.
4. According to claim 1,

   The average thickness of the graphene nanoplatelets is 6-8 nm,

   The average particle size is 5 to 25 μm,

   The specific surface area is 120 to 150 m ² /g,

   polyimide film.
5. According to claim 1,

   The permittivity is 4.0 or more and 7.0 or less,

   Dielectric loss factor is less than 0.01,

   polyimide film.
6. (a) dianhydride components including benzophenone tetracarboxylic dianhydride (BTDA), biphenyltetracarboxylic dianhydride (BPDA) and pyromellitic dianhydride (PMDA), and m-tolidine ( preparing a polyamic acid by polymerizing a diamine component composed of m-tolidine) and paraphenylene diamine (PPD) in an organic solvent;

   (b) adding and mixing graphene nanoplatelets to the polyamic acid; and

   (c) imidizing the polyamic acid containing the graphene nanoplatelets,

   Manufacturing method of polyimide film.
7. According to claim 6,

   Based on 100 mol% of the total content of the diamine component, the content of m-tolidine is 20 mol% or more and 40 mol% or less, and the content of paraphenylene diamine is 60 mol% or more and 80 mol% or less,

   The content of benzophenone tetracarboxylic dianhydride is 20 mol% or more and 45 mol% or less based on 100 mol% of the total content of the dianhydride component,

   The content of biphenyltetracarboxylic dianhydride is 20 mol% or more and 45 mol% or less,

   The content of pyromellitic dianhydride is 20 mol% or more and 45 mol% or less,

   Manufacturing method of polyimide film.
8. According to claim 6,

   The dielectric constant of the polyimide film is 4.0 or more and 7.0 or less,

   Dielectric loss factor is less than 0.01,

   Manufacturing method of polyimide film.
9. Comprising the polyimide film according to any one of claims 1 to 5,

   multilayer film.
10. Including the polyimide film according to any one of claims 1 to 5 and the electrically conductive metal foil,

    Flexible metal clad laminate.
11. Including the flexible metal clad laminate according to claim 10,

    Electronic parts.